/*图片遮罩层*/
.box{
    text-align: center;
    overflow: hidden;
    position: relative;
}
.box:before{
    content: "";
    width: 0;
    height: 100%;
    background: #000;
    padding: 14px 18px;
    position: absolute;
    top: 0;
    left: 50%;
    opacity: 0;
    transition: all 200ms cubic-bezier(0.47, 0, 0.745, 0.715) 0s;
}
.box:hover:before{
    width: 100%;
    left: 0;
    opacity: 0.5;
}
.box img{
    width: 100%;
    height: auto;
}
.box .box-content{
    width: 100%;
    padding: 14px 18px;
    color: #fff;
    position: absolute;
    top: 38%;
    left: 0;
}
.box .title{
    line-height: 30px;
    text-transform: uppercase;
    margin: 0;
    opacity: 0;
    transition: all 0.5s ease 0s;
}

.box:hover .title{
    opacity: 1;
    transition-delay: 0.2s;
}

@media only screen and (max-width:990px){
    .box{ margin-bottom: 30px; }
}